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Vinyls divinylbenzene

The copolymer vinyl-divinylbenzene (DVB)-polydimethylsiloxane (PDMS) PDMS-DVB, a 65 fim thick coating... [Pg.861]

Other developments in chelating resins include fibers made from poly(ethylene glycol) and poly(vinyl alcohol) to which EDA was attached with epichl orohydrin (281) and a styrene—divinylbenzene resin with pendant EDTA or DETPA groups (282). [Pg.48]

Macroporous divinylbenzene gels having a high concentration of chemically and accessibly free vinyl groups can be produced. The gels are prepared... [Pg.8]

It has been suggested that certain 1,5-dienes including o-divinylbenzene (23),156 vinyl acrylate (24, X 11) and vinyl methacrylate (24, X CH )120 may also undergo cyclopolymerization with a monomer addition occurring prior to cyclization and formation of a large ring. However, the structures of these cyclopolymers have not been rigorously established. [Pg.192]

Cornejo et al. [65] reported the first immobihzation of pyridine-bis(oxa-zoline) chiral hgands and the use of the corresponding solid ruthenium complex in the model cyclopropanation test. They synthesized vinyl-PyBOx, the vinyl functionahty being introduced in the fourth position of the pyridine ring. This monomer was further homo- or copolymerized in the presence of styrene and divinylbenzene. The corresponding ruthenium catalysts proved... [Pg.113]

Nonlinear addition polymers are readily obtained by copolymerizing a divinyl compound (e.g., divinylbenzene) with the vinyl monomer (e.g., styrene), as already mentioned. Products so obtained exhibit the insolubility and other characteristics of space-network structures and are entirely analogous structurally to the space-network polymers produced by the condensation of polyfunctional compounds. Owing to... [Pg.54]

CFPs are isotropic materials built up with cross-linked pol5mer chains that are normally originated by the homo-or co-pol5mierization of vinyl monomers, the most important of which is styrene [13]. Similar observations are also valid for the cross-linking agent. In fact, the commonest one is divinylbenzene, but diolefins such as meth-ylenebisacrylamide (MBAA) and ehylenedimethacrylate (EDMA) are also popular (Figure 1) [14]. [Pg.201]

Table 4—3. Amides from l-acyl-4-vinyl imidazole/divinylbenzene copolymer. Table 4—3. Amides from l-acyl-4-vinyl imidazole/divinylbenzene copolymer.
As mentioned before for other azolide reactions, acylations can be carried out with polymer-supported azolides as acylating reagents. For example, acetic acid hydrazide can be prepared with a polymer of l-acetyl-4-vinyl-imidazole/divinylbenzene (96 4) and hydrazine (no diacylation occurs when this method is used) [122]... [Pg.134]

The synthesis of the first polymer-supported chiral Mn-salen derivatives was reported independently by Sivaram171 and Minutolo.171-173 Different monomeric Jacobsen-type units, containing two polymerizable vinyl groups, were copolymerized with styrene and divinylbenzene to yield the corresponding cross-linked polymers as a monolithic compact block.174-176 The less mobile system (Figure 19) with no spacer between the aromatic ring and the polymer backbone is less enantioselective. [Pg.461]

Waters (see 2006-2007 Catalog, SPE products) Oasis HLB Divinylbenzene-N-vinyl-pyrrolidone copolymer Reversed phase with some hydrogen bond acceptor and dipolar reactivity Rosuvastatin (71) NSAIDs (72) fexofenadine (73) catechins (74) valproic acid (75)... [Pg.6]

Divinylbenzene Methyl vinyl ketone Vinyl toluene... [Pg.65]

Figure 1. Role of dose rate in the synergistic effect of divinyl-benzene and sulfuric acid on grafting of styrene on polypropylene film in methanol dose rate of 4.1 x 104rad/hr to total dose of 2.4 x lO rad (A) styrene-methanol, (o) styrene-sulfuric acid (0.2M). ( ) styrene-methanol-divinylbenzene (1% v/v), and (o) styrene-methanol -di vinyl benzene (1% v/v)-sulfuric acid (0.2M). dose... Figure 1. Role of dose rate in the synergistic effect of divinyl-benzene and sulfuric acid on grafting of styrene on polypropylene film in methanol dose rate of 4.1 x 104rad/hr to total dose of 2.4 x lO rad (A) styrene-methanol, (o) styrene-sulfuric acid (0.2M). ( ) styrene-methanol-divinylbenzene (1% v/v), and (o) styrene-methanol -di vinyl benzene (1% v/v)-sulfuric acid (0.2M). dose...
Postpolymerization of difunctional monomers to effect star branching has been successfully applied in cationic polymerization, e.g. in the case of polyisobutylene initiated with 2-chloro-2,4,4,-trimethylpentane/TiCl4. Addition of divinylbenzene leads to star polymers [104], Vinyl ethers, when polymerized with HI/ZnI2 in toluene at — 40°C, can be copolymerized with divinylether... [Pg.83]

Grafting of these preformed monoliths with dormant radicals is achieved by filling the pores with a monomer solution and heating to the desired temperature to activate the capped radicals. For example, a functionalization of poly(styrene-divinylbenzene) monolith with chloromethylstyrene and vinyl-pyridine to obtain material with up to 3.6 mmol/g of functionalities has been demonstrated [88]. [Pg.100]

Porous materials used for chromatography result from a chemically induced phase separation using chain-wise polymerization of vinyl-containing monomers crosslinked with a portion of divinyl functional monomers. Frechet has improved this technique for the preparation of porous PS beads [48]. In this approach the inner phase consists of a mixture containing the reactive styrene and divinylbenzene monomers as well as an unreactive polymeric porogen. After polymerization, the soluble polymeric porogen is removed, leaving behind ma-croporous beads with pore sizes of around 100-500 nm. [Pg.168]

The corresponding catalytic version of this reaction was performed using either naphthalene- or biphenyl-supported polymers 594 or 595, respectively, which were prepared by cross-coupling copolymerization of 2-vinylnaphthalene or 4-vinylbiphenyl with vinyl-benzene and divinylbenzene promoted by AIBN in THF and polyvinyl alcohoP . These polymers have been used as catalysts (10%) in lithiation reactions involving either chlorinated functionalized compounds or dichlorinated materials in THF at —78°C and were re-used up to ten times without loss of activity, which is comparable to the use of the corresponding soluble arenes. [Pg.741]

The first case is the copolymerization of monomer A with diene BB where all the double bonds (i.e., the A double bond and both B double bonds) have the same reactivity. Methyl methacrylate-ethylene glycol dimethacrylate (EGDM), vinyl acetate-divinyl adipate (DVA), and styrene-p- or m-divinylbenzene (DVB) are examples of this type of copolymerization system [Landin and Macosko, 1988 Li et al., 1989 Storey, 1965 Ulbrich et al., 1977]. Since r = Yi, Fi = f and the extent of reaction p of A double bonds equals that of B double bonds. There are p[A] reacted A double bonds, p[B] reacted B double bonds, and p2[BB] reacted BB monomer units. [A] and [B] are the concentrations of A and B double bonds,... [Pg.521]

Because of its chemical inertness, no direct way of curing poly(thiocarbonyl fluoride) has been found. However, creep has been reduced and strength at elevated temperatures improved by milling into the polymer a free-radical generator, such as dicumyl peroxide or azobisisobutyronitrile, and a free-radical acceptor, such as N,N -m-phenylenebismaleimide or triacryloylhexahydro-s-triazine, and curing with heat and pressure (65). A better method is to mill in divinylbenzene and a small amount of benzoyl peroxide and cure with heat and pressure (66). The divinylbenzene forms a crosslinked matrix that mechanically traps poly(thio-carbonyl fluoride) molecules. Since the elastomer is in effect filled with poly(di-vinyl benzene), the final composition is less resilient than untreated poly(thio-carbonyl fluoride). [Pg.96]

Once the vinylbenzylanion (II) forms, it may add to another divinylbenzene molecule resulting in DVB "homopolymerization" (Reaction 2). Likewise, the vinylbenzylanion (II) may attach a pendant vinyl group of another polymer chain (Reaction 3) to give the alkylbenzylanion (III). [Pg.563]


See other pages where Vinyls divinylbenzene is mentioned: [Pg.424]    [Pg.487]    [Pg.163]    [Pg.222]    [Pg.162]    [Pg.207]    [Pg.55]    [Pg.391]    [Pg.161]    [Pg.175]    [Pg.492]    [Pg.147]    [Pg.453]    [Pg.42]    [Pg.362]    [Pg.113]    [Pg.62]    [Pg.123]    [Pg.3]    [Pg.10]    [Pg.34]    [Pg.10]    [Pg.149]    [Pg.540]    [Pg.579]    [Pg.580]    [Pg.333]    [Pg.678]    [Pg.399]    [Pg.558]    [Pg.540]   


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Divinylbenzene

Divinylbenzenes

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